Just back from diving Stuart Cove's on New Providence Island, Nassau. Class A+ operation. Ten dives in five days, reefs, walls, and wrecks. They have a diver check-in system guaranteed not to leave anyone behind. When you exit each dive you have to personally initial the Divemaster's check-in sheet. Then, even when all divers have initialed he calls out name and number before the boat leaves for the next site. All our charter boats should have the same system. Here's a copy of their check-in log: